Effervescent handwash powder laundry detergent

Abstract

The invention relates to an effervescent, high foaming, free-flowing powder laundry detergent suitable for handwashing to remove dirt and stains from laundry. The present invention offers a powder laundry detergent suitable for handwashing that foams quickly without requiring the user to spend time and effort foaming the detergent. This invention also allows laundry to remain soft without becoming stiff during hand washing. The effervescent handwash powder laundry detergent according to the present invention provides ease of use, superior stain removal, softness and savings in both time and effort.

Description

[0001] EFFERVESCENT HANDWASH POWDER LAUNDRY DETERGENT

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention relates to a powder laundry detergent.

[0004] The invention relates to a handwash powder laundry detergent.

[0005] The handwash powder laundry detergent has effervescent effect and its high foam production and superior stain removal performance offer ease of use to the consumer.

[0006] The handwash powder laundry detergent according to the present invention provides a refreshed color appearance to the laundry without fading their colors.

[0007] The handwash powder laundry detergent according to the present invention ensures that the laundry remains soft.

[0008] The improved foam durability, effective cleaning performance and economic feasibility of the compositions claimed according to the present invention result in greater customer appeal.

[0009] BACKGROUND OF THE INVENTION

[0010] Washing clothes by hand is a common practice in some parts of the world for economic reasons, convenience, or both. In the formulation of detergents, foaming or dirt-removing properties are considered extremely important factors, such that a detergent that foams excessively is not an effective cleaning indicator in a washing machine, whereas a significant amount of foam is considered an effective cleaning indicator when hand washing the clothes. Consumer perception of the adequacy of the detergent dosage depends on the amount of foam produced by the detergent. It is therefore essential to develop a detergent composition that produces enough foam to satisfy the consumer, depending on the type of use.

[0011] Consumers adjust the dose of handwash laundry detergent based on the amount and intensity of foam, which increases the cost of the washing process. Therefore, the handwash laundry detergent composition of the present invention will tend to be replaced by other products while offering increased and accelerated foam quantity and lower cost. The pH of a typical laundry detergent is quite high, around 10. In contrast, handwash laundry products are used with water at a temperature that the consumer's hand can withstand, and often provide cold water washing.

[0012] WO 1998 / 046716 relates to effervescent detergent compositions. WO 1998 / 046716 describes the effervescent composition and effervescent granules. However, this composition requires an additional preliminary step and contains percarbonate. The additional preliminary step required for creating the effervescent detergent described in WO 1998 / 046716 entails an extra cost. In addition, the composition containing percarbonate has disadvantages such as declining percarbonate activity over time, difficulties in storage due to gas formation, formulation stability issues, irritation to sensitive skin during hand washing, and cost.

[0013] Producing a detergent composition that provides foam levels with improved durability while maintaining cleaning efficacy during hand washing of white and / or colored fabrics at low washing temperatures has been challenging.

[0014] Therefore, there is a growing need and demand for a percarbonate-free handwash powder composition with high foaming capacity and durability that can be used to remove stains and / or dirt, even in low temperature washes.

[0015] SUMMARY OF THE INVENTION

[0016] The present invention is a free-flowing handwash powder detergent effective on oxygen and mannanase sensitive stains, comprising surfactant, basic effervescent agent and acidic effervescent agent. The present invention comprises a surfactant in an amount ranging from 10% by wt. to 20% by wt., a basic effervescent agent in an amount ranging from 15% by wt. to 30% by wt., and an acidic effervescent agent in an amount ranging from 15% by wt. to 30% by wt. The inventors have achieved high foaming and effective cleaning power with a composition of sodium bicarbonate, citric acid and surfactants in effective ratios.

[0017] The acidic effervescent and basic effervescent agent source of the present invention has been found to exhibit superior stain removal performance without percarbonate on oxygen sensitive and mannanase sensitive stains, exhibiting high foaming with water in combination with surfactant.

[0018] Unlike existing formulations, on the other hand, the invention provides an advantage in increasing the effervescent effect with a lower use of surfactants. It is well known that the increased surfactant content has a negative effect on the effervescent effect. Surfactants act as binders in the effervescent structure and delay foaming.

[0019] The present invention provides the high pH cleaning efficacy of conventional detergents at a lower pH without causing irritation or skin sensitization on the hands. The low pH composition of the present invention has a positive effect on preventing color loss of the laundry upon repeated washing.

[0020] The effervescent structure of the present invention ensures that no residue is formed after washing.

[0021] Additionally, the stain removal results of the present invention without the use of percarbonate and TEAD (tetraacetylethylenediamine) were found to be highly effective compared to other detergents.

[0022] The advantage of the present invention is that, due to its percarbonate-free composition, the performance of removing oxygen- and mannanase-sensitive stains is achieved even at low temperatures. As a further advantage of the present invention, it has been observed that the enzyme-enriched handwash powder laundry detergents known in the art do not cause the color fading problem caused by detergents, thus preserving the vibrancy of the colors.

[0023] DESCRIPTION OF THE INVENTION

[0024] The present invention relates to a high-foaming, free-flowing, effervescent handwash powder detergent effective on oxygen and mannanase sensitive stains.

[0025] The purpose of the invention is to provide a free-flowing handwash powder laundry detergent composition which is effective on oxygen and mannanase sensitive stains, provides easy washing due to its effervescent effect and high foam production, and does not cause color fading and hardening of the laundry upon repeated laundering.

[0026] It has been found that this purpose can be achieved by formulating the anionic surfactant, nonionic surfactant, acid source, carbonate source content with the present invention.

[0027] The composition of the present invention comprises elements which contribute to the formation of the effervescent effect.

[0028] The effervescent effect is created by an acid and a carbonate source.

[0029] According to the present invention, the acid source is organic acid.

[0030] The acids are preferably mono-, bi- or tri-protonic acids.

[0031] Among such preferred acids are mono- or polycarboxylic acids, preferably citric acid, adipic acid, glutaric acid, citramalic acid, tartaric acid, maleic acid, malic acid, succinic acid, malonic acid.

[0032] Such acids are preferably used in the form of acid or acid salt and their anhydrous forms or combinations thereof may be preferred. The most preferred one is the anhydrous from of citric acid.

[0033] According to the present invention, the composition comprises the said acid source in an amount ranging from 10% to 40% by weight of the total composition, preferably from 13% to 35%, and more preferably from 15% to 30%.

[0034] According to the present invention, the carbonate source reacts with the acid source in the presence of water to produce carbon dioxide gas and sodium citrate.

[0035] The carbonate source is preferably selected from alkaline and / or alkaline earth metal salts of carbonate, bicarbonate and the combinations thereof.

[0036] A more preferably selected carbonate source is sodium bicarbonate.

[0037] According to the present invention, the composition comprises said carbonate source or combinations thereof in an amount ranging from 10% to 40% by weight of the total composition, preferably from 13% to 35%, and more preferably from 15% to 30%

[0038] The composition of the present invention comprises surfactants. These surfactants are preferably anionic and non-ionic surfactants. These anionic and nonionic surfactants contribute to cleaning performance.

[0039] In one embodiment of the present invention, the preferred anionic surfactant is linear alkyl benzene sulfonic acid sodium salt (LABSA.Na).

[0040] LABSA.Na is produced by sulfonation of linear alkyl benzene (LAB) producing linear alkyl benzene sulfonic acid (LABSA), which is then neutralized with sodium hydroxide to produce LABSA.Na. The LAB used in the production of LABSA.Na may be of HF and / or Detal type.

[0041] LAB used in the production of LABSA.Na contains a maximum of 1% Cg-phenyl, 8-18% Cio-phenyl, 26-38% Cn-phenyl, 26-38% Ch-phenyl, 15-27% Ci3-phenyl, and a maximum of 1% Ci4-phenyl by total weight of LAB. The 2-phenyl isomer content of LAB may range from 15-22% by weight for HF type and from 25-35% by weight for Detal type.

[0042] The resulting LABSA.Na contains at least 96% solid matter by weight and exhibits a similar carbon distribution to the LAB raw material.

[0043] LABSA.Na is added to detergent compositions before the spray-drying process (i.e., it is present in the slurry to be spray-dried).

[0044] The preferred nonionic surfactant group in the present invention is ethoxylated alcohols.

[0045] Ethoxylated alcohols may be selected from C12-C18 fatty alcohol ethoxylates with 5-9 EO, C13-C15 oxo alcohol ethoxylates with 5-9 EO, and C9-C11 oxo alcohol ethoxylates with 6-10 EO.

[0046] According to the present invention, the preferred nonionic surfactant can be represented by the following formula (a):

[0047] Ri-O-(CH2-CH2-O)mH

[0048] (a) where predominantly unbranched (linear) C13-C15 oxo alcohol and m=3 - 11. A more preferred non-ionic surfactant of the present invention is oxo alcohol ethoxylate, wherein the number of ethoxyl groups (m) in formula (a) is 5 to 7.

[0049] The composition according to the present invention comprises a surfactant in an amount ranging from 10% by weight to 20% by weight. When the surfactant concentration is below 10%, the desired cleaning performance cannot be achieved. Increasing the surfactant concentration beyond 20% does not provide any additional cleaning benefit. In addition, the use of effervescent material in the present invention allows the desired level of cleaning performance to be achieved using a smaller amount of surfactant.

[0050] In one embodiment according to the present invention, the composition comprises a mixture of anionic and nonionic surfactants and the ratio of anionic surfactants to nonionic surfactants in the composition is in the range of 25: 1 to 5: 1, preferably in the range of 12.5: 1 to 6.25: 1.

[0051] The non-ionic surfactant is added to the compositions by a post-addition, which is created after spray drying and cooling to lower temperatures where the non-ionic surfactants are not adversely affected.

[0052] Filler: The present invention contains a filler material constituting between 20% and 45% by weight of the total composition. Accordingly, the filler can be selected from sulfate salts, sodium acetate or sodium chloride. The preferred main filler is sodium sulfate. The present invention contains sodium chloride up to 5.5% by weight. In the present detergent compositions, a small amount of magnesium sulfate, up to 2% by weight of the total composition, is also preferable. Fillers are added to detergent compositions prior to spray drying (i.e. they are present in the spray-dried slurry). Sodium sulfate, which is the main filler, is thought to ensure that the effervescent detergent remains dry thanks to its moisture-absorbing properties and that the effervescent feature is revealed during use. Furthermore, sodium sulfate is a necessary ingredient for granulation.

[0053] In one embodiment according to the present invention, it further comprises zeolite up to 5% by weight of the total composition.

[0054] Optical brightener: The detergent compositions of the present invention may preferably comprise optical brighteners of less than 1.0%, more preferably up to 0.01%, by weight of the total composition. Optical brighteners may be selected from carboxylics such as distyrylbenzenes, distyrylbiphenyls and divinylstilbenes, triazinylaminostilbenes, stilbenyl-2H-triazoles such as stilbenyl-2H-naphthol[l,2- d]triazoles and bis(l,2,3-triazol-2-yl)stilbenes, benzoxazoles such as stilbenyl benzoxazoles and bis(benzoxazoles), furans, benzofurans and benzimidazoles such as bis(benzo[b]furan-2-yl)biphenyls and cationic benzimidazoles, l,3-diphenyl-2- pyrazolines, coumarins, naphthalimides, l,3,5-triazin-2-yl derivatives, methinesyanines, and dibenzothiphen-5,5-dioxide. The optical brighteners preferably used are diphenylethylene triazine and 4,4'-bis(2-sodium sulfonate stryl)biphenyl.

[0055] Sodium silicate added to the present detergent compositions may be represented by the following formula (b): mNaiO nSiOi

[0056] (b) where the ratio n / m is referred to as the modulus of sodium silicate. The present detergent compositions may preferably contain sodium silicate up to 3% by weight of the total composition. The detergent compositions are supplemented with sodium silicate before spray drying (i.e. it is present in the spray-dried slurry).

[0057] Perfumes: Perfume oils and / or encapsulated perfumes may be added to detergent compositions, preferably in the range of 0% to 1% by weight.

[0058] METHOD FOR PREPARING DETERGENT COMPOSITION

[0059] Labsa, sodium silicate, optical brightener, sodium sulfate and water are mixed into a slurry and transported at high pressure to a tower. Inside the tower, it is sprayed, dried at high temperature and thus granulated. The prepared powder is supplemented with zeolite, red sodium chloride, sodium bicarbonate and citric acid and then non-ionic surfactant and perfume are sprayed on it. The mixture prepared as such is stirred in a rotary horizontal mixer and homogenized.

[0060] EXAMPLES

[0061] Example 3 and Example 5 : Represent compositions according to the present invention. Cl- Comparative example 1 (commercially-available effervescent additive-free handwash laundry detergent)

[0062] C2: Comparative example 2 (effervescent additive-free composition)

[0063] FOAMING PERFORMANCE

[0064] The foaming measurements for the effervescent handwash powder detergent were conducted using a 250ml glass graduated cylinder. The operating temperature was 40°C and the water hardness was 45 °F. The samples were weighed on a precision balance (2 grams), and each formulation was measured with at least 5 repetitions. In the graduated cylinder, 200 ml of water was measured under specified conditions, and the weighed samples were carefully poured. After the samples were poured, the rise of the foam was monitored, and comparisons among the formulations were made by reading the graduated cylinder height at the moment the foaming ceased.

[0065] The foam heights of the examples in accordance with the present invention (Example 3 and Example 5) were observed to be favorable, with the optimum value being achieved with Example 5.

[0066] STAIN REMOVING PERFORMANCE

[0067] A stain washing process was performed in the laboratory using EMPA and CFT standard stains using a tergotometer device. Stain washing conditions included 30 minutes, 40°C water temperature, 45°F water hardness, 90 rpm rotation speed and 4 repetitions. The washed fabrics were dried in a clean environment away from daylight, and subsequently, the dY (luminance C) values were measured using a spectrophotometer device. The dY value represents the luminance C difference between the original standard fabric and the washed fabric. The higher the value, the more the color of the washed fabric is considered to be different from the color of the original fabric, i.e. the lighter the color. The stain removal performance on oxygen-sensitive and mannanase-sensitive stains was achieved with the formulation of Example 5, which is in accordance with the best examples of the present invention.

[0068] Textile Color Fastness

[0069] The change in color (fading) of a fabric sample, evaluated in accordance with the AISE Color Protection Test method based on the TS 423-5 EN ISO 105-A05 standard, is calculated by comparing it with an untreated reference of the same characteristics, using an instrumental method (device-assisted) and converting the measurements obtained from the device into scale fastness values. The colors of the fabrics are classified as close and far from the reference example. The fabrics were subjected to evaluation using the Konica Minolta CM-3600d Spectrophotometer following 20 consecutive wash cycles (without intermediate drying) performed at 30°C for 30 minutes under a program with 900 rpm, 45 Fr water hardness, and 100 grams of detergent, followed by in-line drying. 5: Composition suitable for the present invention

[0070] *K 1: enzyme containing, handwash powder detergent

[0071] **K 2: enzyme containing, handwash powder detergent

[0072]

[0073] It has been observed that the formulation of the present invention (Example 5), when compared to market-available detergents containing enzymes (KI, K2), does not cause color fading on fabrics and even enhances their vibrancy.

Claims

CLAIMS1. A fast and persistent foam-forming handwash powder laundry detergent composition effective on tough stains, characterized by comprising: between 10% and 20% by weight of a surfactant, between 15% and 30% by weight of a basic effervescent agent, between 15% and 30% by weight of an acidic effervescent agent.

2. A handwash powder laundry detergent according to Claim 1, characterized in that the equilibrium pH of the composition in a 1% by weight dilution in deionized water is between 5 and 7, preferably between 5.5 and 6.5.

3. A handwash powder laundry detergent according to Claim 1, characterized in that said surfactant comprises an anionic surfactant, a nonionic surfactant or a mixture thereof.

4. A handwash powder laundry detergent according to Claim 3, characterized in that the anionic surfactant is linear alkyl benzene sulfonic acid.

5. A handwash powder laundry detergent according to Claim 3, characterized in that the non-ionic surfactant is ethoxylated alcohols, preferably C12-C18 fatty alcohol ethoxylates with 5-9 EO, C13-C15 oxo alcohol ethoxylates with 5-9 EO, C9-C11 oxo alcohol ethoxylates with 6-10 EO, or a mixture thereof.

6. A handwash powder laundry detergent according to Claim 1, characterized in that the basic effervescent agent is sodium bicarbonate.

7. A handwash powder laundry detergent according to Claim 1, characterized in that it preferably contains sodium bicarbonate in an amount ranging from 20% to 30%.

8. A handwash powder laundry detergent according to Claim 1, characterized in that the acidic effervescent agent is citric acid anhydride.

9. A handwash powder laundry detergent according to Claim 1, characterized in that it preferably contains citric acid in an amount ranging from 20% to10. A handwash powder laundry detergent according to Claim 1, characterized in that it contains zeolite up to 5% by weight.

11. A handwash powder laundry detergent according to Claim 1, characterized in that it contains sodium chloride up to 5,5% by weight.

12. A handwash powder laundry detergent according to Claim 1, characterized in that it contains sodium silicate up to 3% by weight.

13. A handwash powder laundry detergent according to Claim 1, characterized in that it contains optical brightener up to 0,01% by weight.

14. A handwash powder laundry detergent according to Claim 1, characterized in that it contains sodium sulfate ranging from 20% to 45% by weight.

15. A method for producing a handwash powder laundry detergent according to Claim 1, characterized by comprising the following steps: a) Preparing a slurry by combining an anionic surfactant, silicate, optical brightener, sodium sulfate, and water, and transferring the slurry into a tower under high pressure; b) Spraying the slurry in the tower and drying it at high temperature to form granules; c) Adding zeolite, sodium chloride, basic and acidic effervescent agents to the granules; d) Spraying a non-ionic surfactant and perfume onto the resulting mixture.

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